Laminated panel



Patented Novf. 15, 1927.

' entre@ stares HARRY WATSON, F CHELSEA,` MASSACHUSETTS.

LAMINATED PANEL.

Application filed March 11, 1927. Serial No. 174,466.

This invention relates to an improved laminated panel construction which is adaptable to a wide variety oil uses. being particularly advantageous when used tor a door.

The present invention discloses a panel construction which permits the use ot a main lamina or core member with associated laminac ot thinner cross section and which -prevents warping oi' the resulting panel in either direction even under adverse conditions ot heat, moisture, and the like. rllhe means utilized for securing the laminas together so reduces the effective cross section of themain laminas that .the vtendency of the same to warp does not appreciably affect the composite panel;` said means also overcoming any tendency toward relative movement lief tween the plies of the composite panel. The preferred manner ot arriving at this desiiable result is by the provision of keys or splines spaced at modular distances upon either tace ot' adjoining lamin and received in grooves in the main lamina and in corresponding grooves in the associated laminas. Preferably grooves upon opposite faces of the central lamina are located opposite each other so that the section ot thatmember is materially reduced betwen each pair ot `grooves while the thickness of the woodvin the adjoining laminas may be similarly reduced by the corresponding grooves therein. Furthermore, the grooves are arranged to permit drainage of excess agglutinant when the plies are forced together under pressure7 and the keys or splines are advantageous in :facilitating assembly ot outer edging pieces upon the panel.

The above and further advantageous teatures oi the invention will be apparent to those skilled in the art upon a reading oit the subjoined description and claims in conliunction with the accompanying drawings in which i p Fig. l is a broken perspective view oi a portion ot the preferred form ot panel;` and Fig. 2 is a detailed cross sectional view ot the same.

rl"he accompanying drawings disclose a laminated or wooden panel which is formed ot laminas ot' wood, the grain of the woodin adjoining lamina: running in opposite directions. The panel comprises a comparatively thick core member or central lamina l and secondary lamina; 2 ot considerably thinner section upon either tace thereof; while7 it desired, upon the outer Jraces ot laminze 2 may be located the thin wooden plies 3 `and et; the grain of the wood in plies 3 ruiming yin one direction and the grain ot' plies @running inthe opposite direction. Referring more particularly to the sectional view of Fig. 2, it will be apparent that the grain ot' the intermediate lamina l isl par.- allel to the section while the grain ofthe adjoining laminasJ 2 is cut bythe section; the grain of the plies 3 in turn paralleling the section and the grain of plies t being cut by the section.

In order to avoid warping of the resulting panel which is thus formed I secure the laminae 2 to the core member l by the means oi' keys or splines 5. These keys are preferably shaped to extend substantially the entire length ot the lamina-3 2 and engage grooves 6 in these laminte and corresponding grooves 7 in the core member. he keys 5 are arranged to have their grain run longitudinally in the conventional man-ner and in a direc' tion similar to that of the laminze 2. Pret-l erably the combined'depth ot the grooves 6 and 7 is somewhat greater than the depth of the `keys to leave a clearance space at the bottom ot the grooves as designated yby numeral 11. Preferably grooves 7 upon op posite faces of core member l adjom each other or are arranged in pairs so that the section of the central lamina is considerably reduced between each pair of grooves Y, as designated by the numeral v9.

Plies l and 2 and keys 5 have their adjoining faces coated with an adhesive, such as glue, and arethen firmly pressed together; the grooves 6 and 7 then act as ducts'to permit the drainage of excess agglutinant from between the plies, thus avoiding pocketing ot the same as commonly occurs' in the manufacture of ply wood panels.

A panel of this character may conveniently be provided with edging pieces 1 0. These members may conveniently be grooved to lit iirmly about opposite marginal faces of lam ina l, as shown. Preferably plies 3 `and 4t extend outwardly upon either side of the member l() and conceal `the side portions thereof so that the panel as viewed in side elevation has a continuous' surface formed by an outer ply l and so that at the edge of the panel the member and the edges of plies 3 edges of lamina l andlaminae 2 are concealed. The ends of keys 5 are slight-ly spaced trom the edge ot core member l to and 4t may be observed while theV permit the edging pieces readily to be applied thereto. Themembers 10 are easily applied to laminee l and 2 Without `causing relative sliding therebetween due to the positive keying of these laminae to each other.

A laminated panel formed in this manner is adapted to withstand exposure to extremely adverse conditions of moisture and temperature and yet not appreciahly to warp as a result of the same. This advantageous result is attributable to the arrangement of the keyways 6 and 7 and the keys 5 in the main and secondary laniinae l and 2. Not only does the provision of these key- Ways reduce the effective cross section of the laminae which tends to cause warping of the same, but the keys provide additional highly effective means for securing the plics'together so that each lamina is firmly secured to an adjoining laminre in which the grain of the Wood runs in the opposite direction. Furthermore, the arrangement of keys in this manner prevents relative transverse movement between the faces of the lamina; which is a concomitant of warping in certain directions. Since the sides of the grooves in each of the laminas are iirmly glued to the faces of the keys7 each of the sections of the laminae is reinforced by separate Wooden members which are secured to transverse surfaces formed by the sides of the grooves, as Well as being reinforced b y the adjoining lamina which is secured to its faces. Moreover, this forni of securing meansy affords the additional advantage of providing longitudinal grooves for drainage ot excess agglutinant, thus avoiding the formation of pools or blisters of the adhesive lnaterial between faces of adjoining laminations, a fault which is likely to occur in the manufacture of laminated or ply Wood panels. Provision of the clearance spaces at the bottom of the grooves not only permits this advantageous result but also allows normal shrinkage of the panel to take place without being interfered with Y' by the keys or Without causing the keys to so atl'ect the laminas that they are distorted from their original form or original relation to each other.

I claim: y

l. A laminated door comprising adjoining laminas in which the grain of the Wood runs in oppositev directions, a multiplicity of registering grooves in abutting faces of the laminas, keys in said grooves securing the laminas together, said grooves having a depth to reduce the eeet-ive thickness of the laminas by at least one third.

2. A laminated door comprising a main wooden lamina, thinner Wooden laminre at either side of said main lamina `with the grain thereof ruiming substantially at right angles tothat of the main lamina, grooves in opposite faces of said main lamina, said grooves being arranged in pairs and having a depth so that the effective thickness of the lamina is reduced by at least one-third, registeringv grooves in the thinner lamiere, and keys in the grooves securing the laminas together.

2L A laminated panel f :oinprising a central wooden lamina, adjoining wooden lamiere at either side of said central lamina with the grain thereof extending in a quite fflillerent direction than that of the central lamina, grooves in opposite faces of said central lamina, said grooves being of sullicient depth materially to reduce the effective` thickness of the central lamina, registering grrioves in adjoining .faces of the adjoining laminas, the latter grooves being of sullicient depth n1aterially to reduce the cllcctive thickness of these laminas, and keys in the grooves securing` the lamina; to each other, ea h of said keys cutting across the grain of one lamina, the effective thickness of the main lainiua and the added effective thicknesses of thc tivo adjoining lamin being substantially of the same order, whereby the ell'cctive tendency of each lamina to Warp in one direction may be overcome by the resistance to ivarping in that direction of the adjoining lamina or laminas.

el. a laminated door comprising a central Wooden lamina, adjoining wooden larniin'f at either side of said central lamina with the grain thereof running substantially at right angles to that of the central lamina, gror'ives in opposite faces of said central lamina-` said grooves having a considerable depth whereby the ell'cctive thiclzne-ass ofthe central lainna. is materially reduced thereby, registering grooves in the adjoining lamina1 said grooves having a considcrahle depth when by the ell'ective thirkIu-sscs ol` these laniinrc is also materially rcducerh keys in the grooves securing the lamiue together, each of said keys cutting across the grainof one lamina, the total thickness of the thinner laminae being substantially of the order of the thickness of the central lamina so that the laminas may effectively resist the tendencies of each other to warp. 

